There are tools to release the spring couplers for the AC hoses, they are plastic and can be bought cheaply. When you fix the AC system you should also be replacing the accumulator, (also called the receiver/drier) it is the filter of the AC system and contains desiccant to keep moisture from the refrigerant. Make sure you use new seals at each connection and have oil added to the system when it is being recharged. Good luck.